It was actually shot in 3 exposures. Hand-held.
These were all stitched together at once, and the
3 panoramas were rendered separately. Then, I
opened them all in PS and used a gradient mask to
take the "best" parts from each.
Overall, it was a real nightmare doing all this on
such a large image, and I *really* hope that
photoshop cs4 will be fully 64-bit, and able to
utilize lots and lots of RAM!